xxIRT: Item Response Theory and Computer-Based Testing in R

A suite of psychometric analysis tools for research and operation, including:
(1) computation of probability, information, and likelihood for the 3PL, GPCM, and GRM;
(2) parameter estimation using joint or marginal likelihood estimation method;
(3) simulation of computerized adaptive testing using built-in or customized algorithms;
(4) assembly and simulation of multistage testing.
The full documentation and tutorials are at <https://github.com/xluo11/xxIRT>.